1. Field of Invention
The present invention relates to a crossbow and, more particularly, to a crossbow with a robust multi-functional string-pulling unit.
2. Related Prior Art
Taiwanese Patent No. 207344 discloses a crossbow that includes a barrel 10, a wing (not shown) supported on a front portion of the barrel 10, a string (not shown) connected to the wing at two ends, a string-pulling unit 14 supported on the barrel 10, and a trigger 16 connected to the barrel 10. A front sight is supported on a front portion of the barrel 10 while a rear sight is supported on a rear portion of the barrel 10. The string-pulling unit 14 is operable to pull the string to a tight, stressed or loaded status. The trigger 16 is operable to lock or release the string. The string-pulling unit 14 is a substantially U-shaped element made by bending a metal wire or a metal strip. The string-pulling unit 14 includes two shanks each including a crook end 141 for hooking the string.
There are several problems have been encountered in the use of this crossbow. Firstly, biased by the string, the shanks of the string-pulling unit 14 tend to rub the barrel 10 in operation. Such abrasion is harmful for both of the string-pulling unit 14 and the barrel. Moreover, the abrasion causes trouble for an archer who tries to load the crossbow. Secondly, the user can load the crossbow with a bolt or pivot the trigger to release the string before the string-pulling unit is returned to the original position. Hence, there are concerns about the security of the crossbow. Thirdly, the front sight is used for only one purpose.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.